1892.] PUBLIC DOCUMENT — No. 33. 87 



cultivating and of harvesting our different farm crops with 

 the prospect of securing the most satisfactory returns under 

 existing circumstances. 



A better knowledge regarding the particular quality of 

 the various articles of fodder at our disposal improves our 

 chances of supplementing them judiciously and thus econom- 

 ically for different kinds of farm live-stock, as well as for 

 different conditions and functions of the same kind. It fur- 

 nishes, also, a safer basis for the explanation of the results 

 obtained in actual feeding experiments. To study the 

 nutritive value or feeding effect of any of our fodder articles 

 by actual feeding experiments, without learning, as far as 

 practicable, something more definite regarding its peculiar 

 quality or composition, deprives the results obtained largely 

 of their general interest, for they are secured under ill- 

 defined circumstances. The chemical analysis of an article 

 of fodder is for these reasons considered the first step 

 required to render an intelligent interpretation of the results 

 in feeding trials possible. 



Food Constituents. — Actual feeding experiments have 

 shown that three groups of plant constituents, namely, nitrog- 

 enous y non-nitrogenous and mineral constituents, are needed 

 to successfully sustain animal life. No one or two of them, 

 alone, can support it for any length of time. In case the 

 food does not contain digestible non-nitrogenous substances, 

 the fat and a portion of the muscles of the animal on trial 

 will be consumed in the support of respiration before its life 

 terminates. In case digestible nitrogenous constituents are 

 excluded from the diet, the formation of new blood and flesh 

 from the food consumed ceases ; for the animal system, 

 according to our present state of information, is not capable 

 of producing its principal constituents from anything else 

 than the nitrogenous constituents of the plants. 



Herbivorous animals receive these substances directly 

 from the plants ; carnivorous animals indirectly, by feeding 

 on herbivorous animals. We feed, at present, our farm- 

 stock too frequently, without a due consideration of the gen- 

 eral natural law of nutrition ; to deal out our fodder crops 

 only with mere reference to name, instead of making 

 ourselves more familiar with their composition and their 



